Re: Bessel Functions and Thumbscrews

[Robert T. Short]

On 03/11/2012 10:29 AM, PhilipNienhuis wrote:
> (Sorry for reacting a bit late)
>
> The A&S Bessel functions are fairly "rough" approximations.
The octave code is pretty rough too, but it is fairly good and fairly 
fast.  More than good enough for what I am doing.  It would be good to 
have a version of Bessel functions that is more accurate.

This whole thread makes me wonder about the accuracy of everything, 
including sin(), cos(), exp(), etc.  As you pointed out, many of these 
packages were carefully tuned to a particular word size.

I have already spent way more time on this than I really have available 
and I won't be solving all these problems anyway, but this has been a 
very educational exercise.
> Perhaps this NUMAL library can be used for Octave as well. It seems to live
> here these days:
>
> http://www.softwarepreservation.org/projects/ALGOL/applications
>
> and the license seems a bit BSD like.
> Any license gurus who can shed a light here?
I am putting this on my to-do list.  Don't hold your breath though.

Bob